Assets\PlayFabSDK\MultiplayerAgent\PlayFabMultiplayerAgentAPI.cs(197,21): warning CS0618: 'UnityWebRequest.isNetworkError' is obsolete: 'UnityWebRequest.isNetworkError is deprecated. Use (UnityWebRequest.result == UnityWebRequest.Result.ConnectionError) instead.'
Unity has depricated the various isXXXXXError
You should use .result == then select the correct enum value